U.S. patent application number 17/271909 was filed with the patent office on 2021-10-14 for humanized anti-vegfr2 single-chain antibody and use thereof.
The applicant listed for this patent is ZHEJIANG BLUE SHIELD PHARMACEUTICAL CO., LTD.. Invention is credited to Zhigang GUO, Binghui SHEN, Laosheng WU.
Application Number | 20210317217 17/271909 |
Document ID | / |
Family ID | 1000005722624 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210317217 |
Kind Code |
A1 |
GUO; Zhigang ; et
al. |
October 14, 2021 |
HUMANIZED ANTI-VEGFR2 SINGLE-CHAIN ANTIBODY AND USE THEREOF
Abstract
The present invention belongs to the field of antibody drugs,
and relates to a humanized anti-VEGFR2 single-chain antibody and
use thereof. The single-chain antibody comprises a heavy chain
variable region set forth in SEQ ID No. 1 and a light chain
variable region set forth in SEQ ID No. 2, wherein the heavy chain
variable region and the light chain variable region are connected
via a flexible peptide with an amino acid sequence set forth in SEQ
ID No. 3. The present invention also discloses use of the antibody
in preparing a product for inhibiting tumor growth. The antibody
disclosed herein can be used as a medicament for clinical use in
indications caused by neovascularization.
Inventors: |
GUO; Zhigang; (Shaoxing,
CN) ; SHEN; Binghui; (Shaoxing, CN) ; WU;
Laosheng; (Shaoxing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZHEJIANG BLUE SHIELD PHARMACEUTICAL CO., LTD. |
Shaoxing |
|
CN |
|
|
Family ID: |
1000005722624 |
Appl. No.: |
17/271909 |
Filed: |
April 29, 2019 |
PCT Filed: |
April 29, 2019 |
PCT NO: |
PCT/CN2019/084875 |
371 Date: |
February 26, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 35/00 20180101;
C07K 2317/565 20130101; C07K 2317/24 20130101; C07K 2317/622
20130101; C07K 2317/76 20130101; C07K 16/2863 20130101 |
International
Class: |
C07K 16/28 20060101
C07K016/28; A61P 35/00 20060101 A61P035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2018 |
CN |
201811003017.7 |
Claims
1. A humanized anti-VEGFR2 single-chain antibody, comprising a
heavy chain variable region having an amino acid sequence shown as
SEQ ID No. 1 and a light chain variable region having an amino acid
sequence shown as SEQ ID No. 2, wherein the heavy chain variable
region and the light chain variable region are connected via a
flexible peptide having an amino acid sequence shown as in SEQ ID
No. 3.
2. A method for inhibiting tumor growth comprising a step of
administrating a subject needed for the inhibiting tumor growth
with the humanized anti-VEGFR2 single-chain antibody according to
claim 1.
3. The method according to claim 2, wherein the tumor growth is
reflected by an increased volume of the tumor and/or an increased
mass of the tumor.
Description
TECHNICAL FIELD
[0001] The present invention belongs to the field of antibody
drugs, and relates to a fully humanized anti-VEGFR2 single-chain
antibody and use thereof.
BACKGROUND
[0002] Tumor blood vessels provide enough oxygen and nutrition for
the generation and development of tumors, and targeting tumor
angiogenesis can achieve the therapeutic effect of starving tumors.
However, the molecular regulation mechanism of tumor angiogenesis
is so complicated that the mediation of a plurality of growth
factors, receptors and signaling pathways is required.
[0003] In the angiogenesis process, vascular endothelial cell
growth factors (VEGFs) play an important role in strongly
stimulating the proliferation of vascular endothelial cells. The
receptors to which VEGF binds include VEGFR1 (also known as Flt-1)
and VEGFR2 (also known as Flk-1). VEGFR1 and VEGFR2 are in the type
III receptor tyrosine kinase family. Of which, extracellular region
consists of 7 immunoglobulin-like domains and includes a ligand
binding domain and a receptor dimerization domain, middle region
comprises a cell transmembrane domain, and intracellular region
comprises a tyrosine kinase domain. VEGFR2 mediates a variety of
effects of VEGF including endothelial cell proliferation, vascular
proliferation and infiltration, whereas VEGFR1 does not appear to
be directly involved in endothelial cell proliferation and vascular
proliferation. The binding of VEGF dimer to VEGFR2 induces receptor
dimerization and phosphorylation of tyrosine residues in the
intracellular tyrosine kinase domain, thereby activating downstream
signaling pathways, including activation of phospholipase C,
increase of intracellular Ca.sup.2+ concentration and the like,
triggering events including the proliferation and survival vascular
endothelial cells, cytoskeletal rearrangement, cell migration, gene
expression and the like, ultimately leading to vascular
proliferation.
[0004] Bevacizumab, an inhibitor against VEGF, is a recombinant
humanized monoclonal antibody against VEGF developed by Genentech,
which consists of 93% human and 7% mouse sources. Bevacizumab was
approved for marketing in the United States by FDA on Feb. 26,
2004, being the first approved drug to market in the United States
to inhibit tumor angiogenesis. Global sales of bevacizumab were
$556 million in 2004 and up to $7.037 billion in 2013. Ramucirumab,
an inhibitor against VEGFR2, was developed and successfully
marketed by Eli Lilly and Company following its acquisition of
ImClone's IMC-1121B project. Ramucirumab is a fully human IgG1
monoclonal antibody against VEGFR2 that specifically binds to
KDR/VEGFR2. The drug was marketed in the United States in May 2014
for use in advanced or metastatic gastric cancer or adenocarcinoma
of esophagogastric junction.
SUMMARY
[0005] The present invention is intended to provide a humanized
anti-VEGFR2 antibody and use thereof.
[0006] In the method of the present invention, a high-capacity
high-diversity antibody library is constructed, and from which
antibodies that bind to VEGFR2 and can block their binding to
ligand VEGF are screened, and the resulting antibodies have cell
viability.
[0007] The present invention provides a humanized anti-VEGFR2
antibody.
[0008] Provided is an anti-VEGFR2 single-chain antibody, comprising
a heavy chain variable region and a light chain variable region,
wherein the heavy chain variable region and the light chain
variable region are connected via a flexible peptide with an amino
acid sequence set forth in SEQ ID NO. 3.
[0009] The heavy chain variable region can specifically be a
polypeptide set forth in SEQ ID NO. 1 of the sequence listing.
[0010] The light chain variable region can specifically be a
polypeptide set forth in SEQ ID NO. 2 of the sequence listing.
[0011] The monoclonal antibody disclosed herein is fully
humanized.
[0012] CDR1, CDR2 and CDR3 in the heavy chain variable region are
sequentially amino acid residues at positions 26-38, amino acid
residues at positions 53-69 and amino acid residues at positions
102-107 from the N terminus of sequence 1 in the sequence listing;
CDR1, CDR2 and CDR3 in the light chain variable region are
sequentially amino acid residues at positions 24-35, amino acid
residues at positions 51-58 and amino acid residues at positions
93-101 from the N terminus of sequence 2 in the sequence
listing.
[0013] The present invention also discloses use of the anti-VEGFR2
single-chain antibody in preparing a product for inhibiting tumor
growth.
[0014] The tumor growth is reflected in an increased volume of the
tumor and/or an increased mass of the tumor.
[0015] The sequences of the antibody gene variable region involved
in the present invention can construct a full-length antibody
molecule as a medicament for clinical use in indications caused by
neovascularization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an SDS-PAGE electrophoretogram of VEGFR2-specific
single-chain antibody purification.
[0017] FIG. 2 is a graph showing EC50 for different concentrations
of ligands of VEGFR2-specific antibodies.
[0018] FIG. 3 is a graph showing the relationship between tumor
volume and time of administration (AVR2 vs. Avastin).
[0019] FIG. 4 is a graph showing the solid tumor volume change
after administration.
DETAILED DESCRIPTION
[0020] The following examples are intended to facilitate a better
understanding of the present invention, but do not limit the
present invention. Unless otherwise stated, the methods in the
following examples are conventional methods. Unless otherwise
stated, the test materials used in the following examples are
purchased from conventional biochemical reagent stores. In
quantitative tests of the following examples, three replicates are
set up and the results are averaged.
Example 1: Discovery of VEGFR2-Specific Antibodies
[0021] I. Construction of Natural Humanized Single-Chain Antibody
Library
[0022] Peripheral blood was obtained from the volunteers with
informed consent, from which lymphocytes were isolated and total
RNA was extracted. The total RNA was reversely transcribed to
obtain cDNA. The heavy chain and light chain variable regions (VH
and VL) of the antibody were PCR amplified with degenerate primers
using cDNA as a template. The PCR products were subjected to 1.5%
agarose gel electrophoresis, and
[0023] VH DNA and VL DNA were isolated and ligated by overlap PCR
with the gene encoding the flexible peptide (SEQ ID NO. 3) as a
single-chain antibody (scFv) gene. The single-chain antibody genes
from different volunteers were mixed in equal amounts, grouped and
cleaved by restriction enzyme, followed by 1.5% agarose gel
electrophoresis. DNA fragments were isolated and ligated to the
phagemid vector plasmid that has been cleaved by the same
restriction enzyme, and the ligated phagemid vector plasmid was
electrically transferred into E. coli to obtain a phage
single-chain antibody library.
[0024] II. Screening for VEGFR2 Humanized Monoclonal Antibodies
[0025] 1. Phage Display and Panning of Antibody Library
[0026] 100-fold library capacity of bacterial solution of the above
humanized VH and VL single-chain antibody library was seeded in 900
mL of 2YT-AG medium (containing 100 .mu.g/mL ampicillin and 2%
glucose), which was then cultured at 37.degree. C. and 250 rpm
until OD600 was 0.5-0.6. Then helper phages with 100-fold cell
density were added for infection for 0.5 h, and the bacteria were
collected by centrifugation. The cells were resuspended in 900 mL
of 2YT-AK medium (containing 100 .mu.g/mL ampicillin and 50
.mu.g/mL kanamycin), and cultured at 30.degree. C. and 250 rpm
overnight.
[0027] The culture from the previous step was centrifuged at 10,000
rpm and 4.degree. C. for 20 min, and the supernatant was collected,
added with 1/4 volume of PEG/NaCl, mixed well, and left to stand on
ice for 2 h. The mixture was centrifuged at 10,000 g and 4.degree.
C. for 25 min, and the supernatant was discarded. The centrifuge
tube was inverted on sheet paper to remove the liquid. The phage
precipitates were resuspended in 3 mL of pre-cooled 1.times.PBS and
centrifuged at 12,000 g and 4.degree. C. for 5 min, and the
supernatant was transferred to a new 15 mL centrifuge tube to
obtain the first round of initial phages.
[0028] VEGFR2-Fc was used as an antigen to coat an immune tube,
which was then blocked with 3% M-PBS. Then 100.times. library
capacity of the first round of initial phages was added for
antibody-antigen binding, and the unbound phages were washed away
with PBST. The phages were eluted with 0.6 mL of triethylamine for
5 min, and equilibrated with 0.6 mL of 1 M Tris-HCl (pH 7.4). The
eluted phages were used to infect TG1, the eluted products were
amplified, and the phages were precipitated and purified with
PEG/NaCl for next round of screening. A total of 3-4 rounds of
enrichment screening on the phage library were performed. The
antigen amount was decreased sequentially, and the washing
intensity was increased sequentially. The eluted products in each
round were measured for titer.
[0029] 2. Induction of Expression of Monoclones and ELISA
Screening
[0030] The panned bacterial solution with limited dilution was
coated on a plate, and cultured overnight. Monoclones were selected
and cultured overnight in a 96-well deep well plate containing
2YT-AG medium at 0.5 mL/well. The overnight culture was transferred
to a 96-well deep well plate containing 2YT-AG culture medium at
0.5 mL/well in a ratio of 1:10, and cultured until OD600 was
0.5-0.6. Then helper phages were added for infection at 37.degree.
C. for 15 min, and cultured at 37.degree. C. for 45 min. The
bacteria were collected by centrifugation at 4000 g, resuspended in
2YT-AK culture medium (containing 100 .mu.g/mL ampicillin and 50
.mu.g/mL kanamycin), induced overnight at 30.degree. C., and
centrifuged on the next day. The supernatant was transferred to a
clean 96-well deep well plate to obtain monoclonal phage
samples.
[0031] VEGFR2-Fc was used as an antigen to coat a 96-well
microplate, and 50 .mu.L of monoclonal phage samples was added to
each well after the microplate was blocked, followed by incubation
for 1.5 h at 37.degree. C. Then 300 .mu.L of PBST was added to each
well and shaken for 5-10 s before the solution was discarded,
repeating for 3-5 times. After that, 100 .mu.L of PBST diluent of
anti-M13-HRP antibody was added to each well, and incubated at
37.degree. C. for 1 h. Then 300 .mu.L of PBST was added to each
well, and shaken for 5-10 s before the solution was discarded,
repeating for 5 times. 50 .mu.L of TMB color developing solution
was added to each well to develop color for 3-10 min (the specific
color developing time depends on the color developing speed), and
then 50 .mu.L of 1 M H.sub.2SO.sub.4 was added to each well to stop
developing. OD450 values were determined using a microplate reader.
ELISA positive samples were selected according to the ELISA data of
the monoclonal phages. The above overnight culture broth in the
2YT-AG culture medium of the 96-well deep well plate was taken for
sequencing analysis, and the sequence of the unique monoclonal
antibody was obtained and set forth in SEQ ID NO. 6 (consisting of
SEQ ID NOs. 1, 3 and 2).
Example 2: Expression of VEGFR2 Antibodies
[0032] I. Construction of Recombinant Plasmid
[0033] 1. DNA molecule encoding VEGFR2-specific antibody was PCR
amplified using a primer pair of SCFV-F and SCFV-R to obtain PCR
amplification product.
TABLE-US-00001 (SEQ ID NO. 4) ScFv-F: CTACGGCAGCCGCTGGATTG (SEQ ID
NO. 5) ScFv-R: CTCGAGGCCTGAGGAGACGGTGAC
[0034] 2. The PCR amplification product obtained in step 1 was
cleaved with restriction enzymes Nco I and Xho I, and the cleaved
product was isolated.
[0035] 3. The pET28B plasmid (purchased from Novagene) was cleaved
with restriction enzymes Nco I and Xho I, and the vector backbone
was isolated.
[0036] 4. The cleaved product from the step 2 was connected to the
vector backbone in the step 3 to obtain a recombinant plasmid
pET28B-ScFv.
[0037] II. Acquisition of Recombinant Strain
[0038] The recombinant plasmid pET28B-ScFv was transformed into
BL21 competent cells to obtain a recombinant strain.
Example 3: Large-Scale Preparation and Purification of
VEGFR2-Specific Antibodies
[0039] 1. Bacteria stored in a refrigerator at -80.degree. C. were
streaked on a Kan-resistant plate, and cultured at 37.degree. C.
overnight (about 15 h). Monoclones were selected and seeded in 3 mL
of Kan-resistant liquid LB medium, and cultured with shaking at
37.degree. C. and 200 rpm overnight for about 15 h. 1 mL of
bacterial solution was seeded in 100 mL of fresh Kan-resistant
liquid culture medium (1:100), and cultured with shaking at
37.degree. C. and 200 rpm. When OD600 of the bacterial solution
reached 0.6, IPTG mother solution was added to make the final
concentration of 0.5 mmol/L. The mixture was cultured with shaking
at 30.degree. C. and 200 rpm for 3 h, and centrifuged at 4.degree.
C. and 1000 rpm for 10 min to collect bacteria. The bacteria were
resuspended in PBS, and centrifuged under the same conditions to
collect bacteria, which were directly used for bacteria lysis.
[0040] 2. Preparation of sample (using a Sangon Ni-TED pre-loaded
gravity column, 1 mL): the host cell debris was removed by
centrifugation or the like, then passed through a 0.45 .mu.m
microfiltration membrane and diluted appropriately with a binding
buffer. Water washing: the resin was washed with 5-10 fold column
volume of pure water at 50-150 cm/h to remove ethanol.
Equilibration: the medium was equilibrated with 5-10 fold column
volume of a binding buffer at 150-600 cm/h, so as to ensure that
the components and the pH of the solution in the medium are
consistent with those of the sample. Sample loading: the sample was
centrifuged, filtered (0.45 .mu.m) and loaded at a low flow rate.
If the column height is 20 cm, the recommended flow rate is
.ltoreq.150 cm/h, and if the column volume is 1 mL, washing
impurities: impurities were washed with 10-20 fold column volume of
a washing buffer at 150 cm/h to remove non-specifically adsorbed
impure proteins, and the washing buffer was collected for
subsequent analysis. Elution: elution was performed with 5-10 fold
column volume of elution buffer at a low flow rate, and the eluent
was collected, detected with SDS-PAGE (shown in FIG. 1), and
concentrated and desalted using an ultrafiltration tube. The target
protein was stored at -20.degree. C.
Example 4: Binding of VEGFR2 Antibodies to Ligand
[0041] Ligands (VEGFR2 antigens) at different concentrations were
immobilized on a microplate. Then, VEGFR2 antibodies at different
concentrations were added and incubated at 37.degree. C. for 2 h.
The unbound antibodies were washed away. The antibodies that bind
to ligands were detected using anti-human IgG-HRP (from
Invitrogen). The results are shown in FIG. 2. The results showed
that the VEGR2 antibody binds strongly to ligand.
Example 5: Treatment of Breast Cancer with VEGFR2
[0042] Nude mice were purchased from Model Animal Research Center.
Nude mice were inoculated with breast cancer cells, and 2 weeks
later were injected with VEGFR2 antibody and control drugs (FIG.
3). The results showed that VEGFR2 can effectively inhibit tumor
growth, and its effect is superior to Avastin under the test
conditions. FIG. 4 shows the comparison of tumor size in the
treated group and the control group.
Sequence CWU 1
1
61118PRTArtificial SequenceIt is synthesized. 1Glu Val Gln Ile Ser
Glu Ser Gly Val Pro Leu Phe Gln Ser Gly Ala1 5 10 15Ser Cys Arg Gly
Ser Asp Ala Ala Ser Leu Thr Thr Arg Ser Trp His 20 25 30Glu Trp Phe
Ala Ala Thr Trp Ala Arg Ile Ala Tyr Gly Tyr Gly Leu 35 40 45Glu Gly
Phe Ser Gly Leu Thr Phe Asn Gly Ala Ala Tyr Ser Thr Ala 50 55 60Glu
Ser Trp Arg Gly Lys Pro Thr Ile Ser Lys Glu Asn Ser Lys Asn65 70 75
80Thr Leu Tyr Leu Asn Phe Asn Ser Ile Lys Gly Glu Glu Trp Gly Trp
85 90 95Trp Tyr Phe Ala Arg Ala Gln Trp Phe Glu Tyr Trp Gly Phe Gly
Phe 100 105 110Leu Ser Thr Val Ser Ser 1152111PRTArtificial
SequenceIt is synthesized. 2Asp Ile Gln Val Thr Asn Ser Phe Ala Thr
Leu Ser Leu Ala Tyr Ala1 5 10 15Asp Gly Gly Thr Leu Ser Cys Lys Gly
Ser Asn Ser Trp Ser Ser Gln 20 25 30Trp Pro Ala Trp Tyr Asn Asn Arg
Pro Gly Ser Gly Pro Lys Leu Leu 35 40 45Ile Trp Ala Gly Ser Ser Lys
Gly Trp Thr Gly Leu Pro Glu Lys Trp 50 55 60Ala Ala Ser Ala Ser Gly
Thr Glu Phe Thr Leu Thr Ile Ser Lys Ile65 70 75 80Glu Pro Asp Glu
Asp Ser Gly Trp Trp Ala Tyr Cys Asn Gln Pro Glu 85 90 95Ser Leu Gly
Leu Ser Phe Gly Ala Gly Pro Lys Val Glu Ile Lys 100 105
110315PRTArtificial SequenceIt is synthesized. 3Gly Gly Gly Gly Ser
Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser1 5 10 15420DNAArtificial
SequenceIt is synthesized. 4ctacggcagc cgctggattg
20524DNAArtificial SequenceIt is synthesized. 5ctcgaggcct
gaggagacgg tgac 246244PRTArtificial SequenceIt is synthesized. 6Glu
Val Gln Ile Ser Glu Ser Gly Val Pro Leu Phe Gln Ser Gly Ala1 5 10
15Ser Cys Arg Gly Ser Asp Ala Ala Ser Leu Thr Thr Arg Ser Trp His
20 25 30Glu Trp Phe Ala Ala Thr Trp Ala Arg Ile Ala Tyr Gly Tyr Gly
Leu 35 40 45Glu Gly Phe Ser Gly Leu Thr Phe Asn Gly Ala Ala Tyr Ser
Thr Ala 50 55 60Glu Ser Trp Arg Gly Lys Pro Thr Ile Ser Lys Glu Asn
Ser Lys Asn65 70 75 80Thr Leu Tyr Leu Asn Phe Asn Ser Ile Lys Gly
Glu Glu Trp Gly Trp 85 90 95Trp Tyr Phe Ala Arg Ala Gln Trp Phe Glu
Tyr Trp Gly Phe Gly Phe 100 105 110Leu Ser Thr Val Ser Ser Gly Gly
Gly Gly Ser Gly Gly Gly Gly Ser 115 120 125Gly Gly Gly Gly Ser Asp
Ile Gln Val Thr Asn Ser Phe Ala Thr Leu 130 135 140Ser Leu Ala Tyr
Ala Asp Gly Gly Thr Leu Ser Cys Lys Gly Ser Asn145 150 155 160Ser
Trp Ser Ser Gln Trp Pro Ala Trp Tyr Asn Asn Arg Pro Gly Ser 165 170
175Gly Pro Lys Leu Leu Ile Trp Ala Gly Ser Ser Lys Gly Trp Thr Gly
180 185 190Leu Pro Glu Lys Trp Ala Ala Ser Ala Ser Gly Thr Glu Phe
Thr Leu 195 200 205Thr Ile Ser Lys Ile Glu Pro Asp Glu Asp Ser Gly
Trp Trp Ala Tyr 210 215 220Cys Asn Gln Pro Glu Ser Leu Gly Leu Ser
Phe Gly Ala Gly Pro Lys225 230 235 240Val Glu Ile Lys
* * * * *